Warp stop-motion for looms



No. 622,462. Patented Apr. 4, I899. J. A, GRAF.

WARP STOP MOTION FOR LOOMS.

(Application filed Nov. 4, 1898.)

(No Model.)

lUNlTE-D STATES PATENT JOI'IANN ADAM GRAF, OF MANCHESTER, NEW HAMPSHIRE.

WARP STOP-MOTION FOR LOOlVlS.

SPECIFICATION forming part of Letters Patent No. 622,462, dated April 4, 1899.

Application filed November 4, 1898. Serial No. 695,424. (No model.)

To ctZZ whom it may concern:

Be it known that I, J OHANN ADAM GRAF, of Manchester, county of Hillsborough, State of New Hampshire, have invented an Improvement in arp Stop-Motions for Looms, of

of the loom is effected by or through the move-' ment into abnormal position of one or more detectors the latter are controlled by and held normally in inoperative position by the unbroken and properly taut warp-threads. One form of such a stop-motion apparatusis shown in United States Patent No. 536,969, dated April 2, 1895, wherein each harness or heddle frame is provided with a series of thin flat sheet-metal detector-heddles having each a warp-eye and a longitudinal slot, a transverse bar of the frame passing through these slots. As is well known, the detector-heddles have a limited vertical movement independent of the heddle-frame owing to the slots being longer than the depth of the bar, so that upon breakage or undue slackening of a warpthread its detector-heddle will drop into abnormal operative position to engage and stop the movement of a normally-vibrating feeler to thereby effect through suitable means the stoppage of the loom. In practice the detector-heddlesare preferably made of hardened steel to secure combined light weight and strength and to resist the wear induced by the friction of the warp-threads passing through them. Avery peculiar and objectionable feature results from the use of suchdetector-heddles-viz. ,their magnetization to a greater or less extent producing certain faults in the cloth unless corrected. Heretofore it has been necessary to remove the hed dies and demagnetize them when the effect on the cloth due to magnetism manifests itself, a proceeding at once inconvenient, expensive, and productive of great loss of time in weaving.

When the heddles become magnetized, their movements become very irregular, so that some of those in the series will lag or drag behind their fellows as the frames are reciprocated to change the shed and. the warpthreads of the lagging heddles will be subjected to greater tension than the other threads, so that the face of the cloth will present a wavy or irregular appearance due to the fact that the filling-threads are more tightly bound by some of the warp-threads than by others, and the value of the cloth varies correspondingly with the irregularity in appearance referred to.

My present invention has for its object the production of means for effecting the movement of the heddles in unison and in alinement at every stroke, whereby it is i1npossible for a heddle to lag and so subject its warpthread to additional and improper tension either as the result of magnetization of the heddles or from any other cause.

' By my invention I also reduce toa minimum the use of the demagnetizing operation.

Figure 1, in front elevation and centrally broken out, represents a sufficient portion of the warp-stop-motion mechanism of a 100111 to be understood with one embodiment of myinvention applied thereto. Fig. 2 is a cross-sec tional View of said mechanism on the line on m, Fig. 1, looking toward the left; and Fig. 3 is an enlarged detail, to be referred to.

The stands A, erected on the loom-frame On the upper bar 11 of the harness-frame the series of metallic detectors d are strung, said bar passing through the longitudinal slots d in the heddles, the latter being provided with warp-eyes (1 as usual.

In the present embodiment of my invention I have attached to the upper ends of the side bars I) of the frames upright guides or standporting-bar the evener 0 will move with the heddles and preserve them in alinement from end to end of the series.

In Figs. 1 and 2 the frames are shown in position to close the shed, and it will be obvious that when one frame rises its support ing-bar b will lift all of its heddles to move their warps into the upper plane of the shed. Now when this frame thereafter descends magnetization of its heddles would tend to cause someof them to lag behind the others, and thereby unduly stretch their warpthreads, so that when the shed was closed the latter would be looser than others; but by my invention the evener follows the heddles and compels such as tend to lag to move in complete unison and alinement with all their fellows, so that all warp-threads arrive at the crossing-point of the shed under the same tension. Again, from the position shown, when the frame descends its transverse bar will move down independently of the heddles until it engages the bottoms of the heddle-slots, the heddles being held up by the tension of the warpthreads, and during such movement the parts 0 of the guides or standards slide through the holes in the evener 0 the latter resting on the tops of the heddles. After the frame has completed its downstroke and begins to rise the tension of the warp-threads usually maintains the heddles up against the under edge of the supporting-bar for part of in alinement.

When the frame descends, the weight of the evener will prevent lagging of heddles; but

I it will not press so heavily as to depress the heddles against warp tension, and thereby interfere with their drop into detaching position upon failure or undueslackness of one or more warp-threads.

7 It will be obvious, from the foregoing that the detectors will be'uncontrolled by their supporting-bar for a short period during each stroke of said bar, and at such period the evener assumes control of the detectors for the purpose set forth.

My invention is not restricted to the precise construction and arrangement herein shown,

for so far as I am aware it is broadly new to provide warp-stop-motion detectors with means to maintain them in alinement and efiect their movement in unison when uncontrolled by their support.

I have shown my invention as applied to detectors serving also as heddles; but it will be obvious that my invention is equally applicable in those constructions where the detectors have a reciprocating movement imparted to them corresponding to the shed formation, even though the detectors are entirely independent of the heddles.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a warp stop-motion for looms, aseries of detectors longitudinally movable into operative position by breakage or undue slackness of the warp-threads, a reciprocating support for said detectors and relatively to which they have a limited independent vertical movement, and means movable relatively to said support, to act upon and insure move ment of the detectors in unison and maintain them in alinement when uncontrolled by their support. I

2. In a warp stop-motion for looms, a series of longitudinally-slotted detectors normally held in inoperative position by the warpthreads, a reciprocating supporting-bar extended through the slots of the detectors and relative to which they have a limited independent longitudinal movement, upright ing a limited independent vertical movement,

and means carried by said frame to act upon the detectors and insure their movement in alinement, to thereby obviate unequal strain upon the warp-threads due to lag of one or more detectors.

4. In a loom, shed-forming mechanism, includin g vertically-reciprocatin g frames,ser.ies of steel detector-heddles carried thereby and having limited vertical movement relative to the frames, and an evener rod or bar movable independently of the frame, to rest on the upper ends of and maintain said detector-- heddles in alinement.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

J OIIANN ADAM GRAF, Witnesses:

JAMEs P. TU'ITLE, HARRY W. SPAULDING. 

